Administering Oracle Data Guard Application Resource Groups

To make an application highly available, you must ensure that the application
is managed as a resource in an application resource group. Unlike other data
replication modules, the Oracle RAC server proxy resource group is not added to the protection
group. Instead, a shadow RAC server proxy resource group is added to represent this resource group.

You can add and remove the Oracle shadow RAC server proxy resource group to and from the protection
group at any time without affecting the Oracle Data Guard data replication. This fact
does not prevent you from adding other, non-RAC server proxy resource groups to the protection
group if necessary. However, these applications cannot use any data that requires
replication to the standby cluster as only Oracle Data Guard is supported in this
type of protection group.

You need to replicate, on the standby cluster, all entities that you
configure for the primary cluster's application resource group. Examples of
entities that you need to replicate are application data resources, configuration
files, and resource groups. Resource group names must also match on both clusters.
In addition, the data that the application resource uses needs to be replicated
on the standby cluster.

How to Add an Application Resource Group to an Oracle Data Guard Protection
Group

Before You Begin

You can add an existing resource group, other than an Oracle RAC server proxy resource group containing
an Oracle RAC server proxy resource, to the list of application resource groups for
a protection group. If you do try to add an Oracle RAC server proxy resource group, the geopg command returns an error.

Before you add an application resource group (of any other type) to
a protection group, ensure that the following conditions are met:

The protection group is defined.

The application resource group does not need any data replicating.
You are not prevented from adding such resource groups, but the Oracle Data Guard module
does not coordinate the switchover of other types of data replication.

The resource group to add already exists on both clusters
and is in an appropriate state.

The Auto_start_on_new_cluster property
of the resource group is set to False. You can determine
the setting of this property by using the clresourcegroup show command.

Setting the Auto_start_on_new_cluster property to False prevents the Sun Cluster resource group manager from automatically
starting the resource groups in the protection group.

When the
protection group is activated, application resource groups need to be online
only on the primary cluster.

The application resource group does
not have dependencies on resource groups and resources outside of this protection
group unless the External_Dependency_Allowed protection
group property is set to TRUE. To add several application
resource groups that share dependencies while the External_Dependency_Allowed protection group property is set to FALSE, you
need to add all the application resource groups that share dependencies to
the protection group in a single operation. If you add the application resource
groups separately, the operation fails.

The protection group can be activated or deactivated, and the resource
group can be either Online or Unmanaged.

If the resource group is Unmanaged and the protection
group is activated after the configuration of the protection group has changed,
the local state of the protection group becomes Error.

If the resource group to add is Online and the protection
group is deactivated, the request is rejected. Before you add an online resource
group, you need to activate the protection group.

Specifies the name of the application resource group. You
can specify more than one resource group in a comma-separated list.

protectiongroup

Specifies the name of the protection group.

This command adds an application resource group to a protection group
on the local cluster. If the partner cluster contains a protection group of
the same name, the command then propagates the new configuration information
to the partner cluster.

If the add operation is unsuccessful on the local cluster, the
configuration of the protection group is not modified. Otherwise, the Configuration is added and its status is set to OK on the
local cluster.

If the Configuration status
is set to OK on the local cluster, but the add operation
is unsuccessful on the partner cluster, the Configuration is
added on the partner cluster and the configuration status is set to Error on the partner cluster.

After the application resource
group is added to the protection group, the application resource group is
managed as an entity of the protection group. Then, the application resource
group is affected by protection group operations such as start, stop, switchover,
and takeover.

Example 2–5 Adding an Application Resource Group to an Oracle Data Guard Protection Group

This example shows how to add two application resource groups, apprg1 and apprg2, to sales-pg.

phys-paris-1# geopg add-resource-group apprg1,apprg2 sales-pg

How to Delete an Application Resource Group From an Oracle Data Guard Protection
Group

You can remove an application resource group from a protection group
without altering the state or contents of the application resource group.
You can remove Oracle shadow RAC server proxy resource groups at any time, without affecting the Oracle RAC server proxy resource groups or Oracle RAC databases
that they represent. You can remove these resource groups because the shadow RAC server proxy resource groups simply
reflect the status of the real Oracle RAC server proxy resource groups and do not control
the Oracle RAC databases.

Before You Begin

Ensure that the following conditions are met:

The protection group is defined on the local cluster.

The resource group to remove is part of the application resource
groups of the protection group. For example, you cannot remove a resource
group that belongs to the data replication management entity.

You can specify more than one resource group in a comma-separated list.

protectiongroup

Specifies the name of the protection group.

This command removes an application resource group from a protection
group on the local cluster. If the partner cluster contains a protection group
of the same name, the application resource group is also removed from the
protection group of the partner cluster.

If the resource group
that is being removed shares dependencies with other resource groups in the
protection group and the External_Dependency_Allowed protection
group property is set to FALSE, you also need to remove
all other resource groups that share dependencies with the resource group
that is being removed.

If the remove operation fails on the local
cluster, the configuration of the protection group is not modified. Otherwise,
the Configuration is removed and its status is set to OK on the local cluster.

If the Configuration status
is set to OK on the local cluster, but the remove operation
is unsuccessful on the partner cluster, the Configuration is
removed from the partner cluster and the configuration status is set to Error on the partner cluster.

Example 2–6 Deleting an Application Resource Group From a Protection Group

This example shows how to remove two application resource groups, apprg1 and apprg2, from sales-pg.